David Hahm, “The Fifth Element in Aristotle’s De Philosophia: A Critical Reexamination.” Published in Journal of Hellenic Studies 1982, reprinted in John P. Anton & Anthony Preus, eds.1983. Essays in Ancient Greek Philosophy, vol. 2. SUNY, 404-428. The distributed version has the title “Aristotle’s De Philosophia and the Introduction of the Fifth Element.” Professor of Classics Emeritus at The Ohio State University. Short bio available on the classics.osu.edu site.